/*
 * Copyright  1990-2009 Sun Microsystems, Inc. All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version
 * 2 only, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License version 2 for more details (a copy is
 * included at /legal/license.txt).
 *
 * You should have received a copy of the GNU General Public License
 * version 2 along with this work; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
 * Clara, CA 95054 or visit www.sun.com if you need additional
 * information or have any questions.
 */

package javax.microedition.sensor;

import java.util.*;

public class Unit {
    private static Hashtable unitTable = new Hashtable();
    
    private String symbol;
    
    private Unit(String s) {
        symbol = s;
    }
    
    public static Unit getUnit(java.lang.String symbol) {
        if (symbol == null) {
            throw new NullPointerException();
        }
        
        if (symbol.length() == 0) {
            throw new IllegalArgumentException();
        }
        
        synchronized (unitTable) {
            Unit unit = (Unit)unitTable.get(symbol);
        
            if (unit == null) {
                unit = new Unit(symbol);
                unitTable.put(symbol, unit);
            }

            return unit;
        }
    }
    
    public java.lang.String toString() {
        return symbol;
    }
}